Publisher’s Note: Nancy Cartwright argues for a novel conception of the role of fundamental scientific laws in modern natural science. If we attend closely to the manner in which theoretical laws figure in the practice of science, we see that despite their great explanatory power these laws do not describe reality. Instead, fundamental laws describe highly idealized objects in models. Thus, the correct account of explanation in science is not the traditional covering law view, but the ‘simulacrum’ account. On this view, explanation is a matter of constructing a model that may employ, but need not be consistent with, a theoretical framework, in which phenomenological laws that are true of the empirical case in question can be derived. Anti?realism about theoretical laws does not, however, commit one to anti?realism about theoretical entities. Belief in theoretical entities can be grounded in well?tested localized causal claims about concrete physical processes, sometimes now called ‘entity realism’. Such causal claims provide the basis for partial realism and they are ineliminable from the practice of explanation and intervention in nature.

Comment: Essential reading on realism and anti-realism about the laws of nature. Recommended for undergraduates who have prior knowledge of Humeanism about laws and for postgraduates in general. The book consists of a series of philosophical essays that can be used independently.

Abstract: In this paper the author discusses and evaluates different arguments for the view that the laws of nature are metaphysically necessary. She conclude that essentialist arguments from the nature of natural kinds fail to establish that essences are ontologically more basic than laws, and fail to offer an a priori argument for the necessity of all causal laws. Similar considerations carry across to the argument from the dispositionalist view of properties, which may end up placing unreasonable constraints on property identity across possible worlds. None of her arguments preclude the possibility that the laws may turn out to be metaphysically necessary after all, but she argues that this can only be established by a posteriori scientific investigation. She argues for what may seem to be a surprising conclusion: that a fundamental metaphysical question – the modal status of laws of nature – depends on empirical facts rather than purely on a priori reasoning.

Comment: An excellent paper that could serve as further or specialized reading for postgraduate courses in philosophy of science, in particular, for modules related to the study of the laws of nature. The paper offers an in-depth discussion of essentialist arguments, but also touches upon many other fundamental concepts such as grounding, natural kinds, dispositions and necessity.

Summary: In this paper, Vetter looks at the argument for Dispositional Essentialism (DE) that has been put forward by A. Bird in his recent book Nature’s Metaphysics. Bird’s overall argument comes in two parts, one negative and one positive, which together are to establish DE as the best contender for a theory of properties and laws. Vetter argues that, even if all their particular steps go through, both parts of the argument have significant gaps. The negative argument, if successful, shows that at least one property has an essence, but not that any property has a dispositional essence. The positive argument, which aims to demonstrate the explanatory power of DE, fails to take account of the quantitative nature of the fundamental natural properties and laws. The paper finishes by suggesting a revision of DE’s doctrine that might solve the latter problem, but yet remains to be spelled out.

Comment: This paper explores in detail the metaphysics of dispositions. It is a good secondary reading for those who have already read Armstrong or Alexander Bird. Vetter writes in a very clear way, but a basic background in metaphysics might be needed to fully understand the paper. This reading is then more suitable for postgraduate courses in metaphysics or philosophy of science.